Diagnostic catheter using a vacuum for tissue positioning

ABSTRACT

A diagnostic catheter using a vacuum for tissue positioning is provided. A method for analyzing tissue in accordance with one embodiment of the present invention includes inserting a catheter having a sensor at its distal end into the body of a patient. Applying suction through the catheter to draw tissue into a predetermined sensing position for the sensor and then analyzing the tissue with the sensor. An apparatus for testing tissue within the body of a patient in accordance with an alternative embodiment of the present invention includes a catheter having a first end and a second end, the first end having an orifice and also having a sensor, the orifice in fluid communication with a vacuum channel.

FIELD OF THE INVENTION

The present invention is directed to the analysis of internal tissue ofa patient. More particularly the present invention regards the use of avacuum within a patient's body to secure tissue near a diagnosticsensor.

BACKGROUND OF THE INVENTION

Diagnostic procedures to analyze and diagnose a patient are a commoncomponent of modern medical care. There are numerous diagnosticprocedures that can be performed on a patient. Some of these diagnosticprocedures, such as x-ray and Magnetic Resonance Imaging, are performedcompletely outside of the body while others, such as tissue biopsies andin situ analysis, require entry into the body and more direct contactwith the suspect body part. Those procedures that require more directtissue contact may be performed through the esophagus and other existingorifices in the patient or through incisions, both small and large, madein the body of the patient.

Whether the diagnostic procedure is performed through an existingorifice or through an incision in the body of the patient, the tissue tobe analyzed may often be out of the direct reach of the practitioner. Inthese situations, in order to reach and analyze the tissue, thepractitioner will often employ an instrument having sensors at itsdistal end. When an instrument is employed the practitioner mustmanipulate and guide the instrument from outside the body in order toposition the sensors, located at its distal end, next to the suspecttissue. This manipulation and steering of the instrument is often atime-consuming and cumbersome process.

For example, when tissue is analyzed during an endoluminal procedure,the practitioner must manipulate the medical instrument containing thesensor within the tight quarters of the endoscope. Once the sensor isproperly positioned by the practitioner, it must then be maintainedadjacent to the tissue in order to receive satisfactory results. In somecircumstances the practitioner may not be able to satisfactorilymanipulate the sensor in order to position it near the tissue to beanalyzed. Similarly they may not be able to satisfactorily maintain thecontact between the tissue and the instrument during the analysis. Toresolve both of these problems, a second instrument, having a hook atits distal end, has been employed. This second instrument is inserteddown into the endoscope in order to hook the tissue, move it next to thesensor, and hold the tissue in place during the testing. The applicationof this second instrument, although frequently used, is disfavored asits use is time consuming and can injure and permanently damage thetissue being tested.

In another example, when diagnostic testing is performed without anendoscope, directly through an incision into the patient's body, thepractitioner must also position the sensor adjacent to the suspecttissue and may also be required to hold the tissue in direct contactwith the catheter in order to perform the analysis. Here, too,positioning the catheter and maintaining its direct contact with thetissue is an arduous and tedious process. A second instrument, such asthe hook described above, is often used to grab the tissue, tug it tothe sensor and anchor the tissue in direct contact with the catheter. Asin the endoluminal procedure, the use of this second instrument, thehook, prolongs the procedure and increases the risk of injury to thetissue.

As is evident, what is needed is a method and an apparatus that providesfor the diagnosis of suspect and diseased tissue within the body of apatient without the cumbersome, time-consuming, and risky proceduresthat have been employed in the past.

SUMMARY OF THE INVENTION

In accordance with the present invention a diagnostic catheter using avacuum for tissue positioning is provided. A method for analyzing tissuein accordance with one embodiment of the present invention includesinserting a catheter having a sensor at its distal end into the body ofa patient. Applying suction through the catheter to draw tissue into apredetermined sensing position and then analyzing the tissue with thesensor.

An apparatus for testing tissue within the body of a patient inaccordance with an alternative embodiment of the present invention isalso provided. This alternative embodiment includes a catheter having afirst end and a second end, the first end having an orifice and alsohaving a sensor, the orifice in fluid communication with a vacuumchannel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a catheter in accordance with a first embodiment of thepresent invention.

FIG. 2 is a cross-sectional view along line 2—2 of FIG. 1.

FIG. 3 is an enlarged view of the catheter from FIG. 1 after beingplaced next to tissue to be analyzed.

FIG. 4 is an enlarged view of the catheter from FIG. 1 wherein a vacuumforce has been used to draw tissue down and in contact with thecatheter.

FIG. 5 is the distal end of an endoscope containing a catheter inaccordance with a second embodiment of the present invention.

FIG. 6 is a catheter employing a syringe to create a vacuum force inaccordance with a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of the distal end of a catheter inaccordance with a fourth embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 illustrates a catheter 10 in accordance with a first embodimentof the present invention. This catheter 10, which may be tube-shaped andmay have a 2-3 mm external diameter, contains a hollow cylindricaldistal tip 120 as well as a hollow cylindrical catheter body 190 and ahollow cylindrical tube 185. The distal tip 120 contains four equallysized orifices 100 along its surface. These orifices 100, which may be0.5 mm in diameter, penetrate completely through one of the walls of thecatheter's 10 hollow cylindrical distal tip 120 and may be spaced adiameter apart from one another. The hollow cylindrical distal tip 120also contains three sensors 110 affixed to its surface and equallylocated between the four orifices 100. These sensors 110 may be numeroustypes of sensors including electrical sensors that test the voltage dropacross the tissue being tested, ultrasound sensors, such as the BostonScientific/SCIMED UltraCross® TX200 transducers, which employ soundwaves to analyze the tissue, and optical sensors, which employ visibleor non visible light to sense the properties of the tissue beinganalyzed. These sensors 110 are connected to sensor line 195 which islocated within the distal tip 120, the catheter body 190, and thecoupler 180. This sensor line 195 connects the sensors 110 with thesensor communication cable 130. The sensor communication cable 130 is inturn connected to a sensor output device (not shown) such as a cathoderay tube. Dependent upon the type of sensors 110 employed the sensorline 195 and the sensor communication cable 130 may be electrical wires,optical fibers, or some other communication link.

As can be seen, a vacuum hose 160 is also connected to the coupler 180.In addition to being connected to the coupler 180 on one end, the vacuumhose 160 is also connected to a vacuum pump, which is not shown, at theother end. This vacuum pump, although not illustrated, may be a 1180Gomco suction unit, capable of creating a vacuum between 0 and 22 in.Hg, and having a bottle coupled to it to prevent solids and liquids fromentering the pump. This vacuum pump is used to create an inward suctionforce through the orifices 100 located at the distal tip 120 of thecatheter 10. This inward vacuum force generated by the vacuum travelsfrom the vacuum pump through the vacuum hose 160, through the firstvacuum channel 165 located in the coupler 180 and the tube 185, throughthe suction adjustment valve 175, back through the tube 185, this timein the second vacuum channel 155, which is located within the tube 185,through the coupler 180, the catheter body 190, and the distal tip 120,such that the vacuum force is in fluid communication with the orifices100.

A suction adjustment knob 170 is rotationally connected to the suctionadjustment valve 175. This suction adjustment valve 175 regulates theamount of suction from the vacuum pump (not shown) that will betransferred from the first vacuum channel 165 to the second vacuumchannel 155 and eventually to the orifices 100 located in the distal tip120 of the catheter 10. By turning the suction adjustment knob 170 thesuction adjustment valve 175 is opened or closed and the amount ofsuction drawn through the orifices 100 at the distal tip 120 of thecatheter 10 is either concomitantly increased or decreased.

In practice a practitioner utilizing the catheter 10 of FIG. 1 mayinsert the catheter 10 into the body of the patient through an existingorifice or through an incision made specifically for the procedure. Thepractitioner would then position the distal tip 120 of the catheter 10,which is made from a flexible polymer, allowing the practitioner to bendand flex the catheter next to the tissue to be diagnosed. Then, once thecatheter's 10 distal tip 120 is in its desired position, thepractitioner would then turn the vacuum pump on and adjust the amount ofvacuum that will be drawn through the orifices 100 at the distal tip 120of the catheter 10 by turning the suction adjustment knob 170. As thepractitioner rotates the suction adjustment knob 170 and increases thevacuum drawn through the four orifices 100, the tissue to be analyzed isdrawn towards the orifices 100 and, consequently, towards the sensors110. Once the suspect tissue has been repositioned and comes in contactwith the sensors 110 the strength of the vacuum force may be maintainedor it may be reduced by the practitioner to a level sufficient tomaintain the contact between the tissue and the sensors 110. By reducingthe vacuum force holding the tissue to the sensors 110 the concentratedforces on the tissues are reduced. The distal tip 120 of the catheter 10and the sensors 110 will remain in contact with the tissue for theduration of the analysis.

Once the requisite analysis and diagnosis has been completed the vacuummay be reduced by turning the suction adjustment knob 170 or by turningthe vacuum off, and the tissue will be free to revert back to itsoriginal resting position within the body. Once the tissue is releasedfrom the orifices 100 the catheter 10 can be removed from the patient orthe procedure can be repeated again, as many times as required, fordifferent sections of tissue.

FIG. 2 is a cross-sectional view taken along line 2—2 of FIG. 1. As canbe seen the distal tip 120 of the catheter 10 has a circularcross-section and the orifice 100 penetrates through the surface and theinner wall 200 of the distal tip 120. The sensor line 195 as well as thesecond vacuum channel 155 are also evident in FIG. 2.

FIG. 3 is an enlarged view of the distal tip 120 of the catheter 10after it has been positioned near a tissue 330 within the body of thepatient. Inward force arrows 320 are clearly shown. The inward forcearrows 320 highlight the position of the downward force created throughthe plurality of orifices 100 by the vacuum being drawn through thesecond vacuum channel 155. The direction of the vacuum forcecommunicated from the vacuum pump through the catheter to the secondvacuum channel 155 is illustrated by arrow 360.

In practice, and as discussed above, as the amount of vacuum isincreased the tissue 330 is drawn down to the orifices 100 until thetissue 330 meets the sensors 110. The sensors 110, now touching thetissue, analyze the tissue and output their results to sensorelectronics, including the cathode ray tube discussed above. Once therequisite data is obtained the vacuum is reduced, the tissue 330 isreleased, and the catheter may be removed or the procedure can berepeated again on a different area of tissue.

FIG. 4 illustrates the distal tip 120 of the catheter after the suctionbeing drawn down the second vacuum channel 155 has been increased, asshown by arrow 400, the suction now drawing the tissue 330 down and incontact with the sensors 110. The contact points between the sensors 110and the tissue 330 are highlighted by arrows 410.

FIG. 5 illustrates the distal end 595 of a second embodiment of thepresent invention wherein a catheter 565 is inserted into the internalworking channel 570 of an endoscope 510. As can be seen, a light tip 520of a light pipe 580 is located at the distal end 595 of the endoscope510. This light tip 520 is connected the light pipe 580 which isconnected to a light source located at the proximate end of theendoscope (not shown). Also located at the distal end 595 of theendoscope 510 is an optical sensor 530. The optical sensor 530 isconnected to a communication line 590 which links the optical sensor 530to the proximate end of the endoscope 510 (not shown) and allows theimages gathered by the optical sensor 530 to be viewed by thepractitioner on a nearby display screen. This optical sensor 530 may beused to assist the practitioner in navigating the distal end 595 of theendoscope 510 to the tissue to be analyzed or alternatively it may beutilized to inspect tissue being analyzed by the sensors 550 located onthe distal tip 560 of the catheter 565.

As is evident, the catheter 565 is located within the internal workingchannel 570 of the endoscope 510. The distal tip 560 of the catheter 565extends from the distal end 595 of the endoscope 510 in thisillustration. As in the previous embodiments, the distal tip 560contains several orifices 540, three in this embodiment, as compared tothe four orifices utilized in the embodiment described above. The distaltip 560 also contains two sensors 550 as compared to the three employedin the first embodiment.

A practitioner using this second embodiment would first insert thecatheter 565 into the internal working channel 570 at the proximate end(not shown) of the endoscope 510. The catheter 565 would only partiallybe inserted into the internal working channel of the endoscope 510 suchthat the distal tip 560 of the catheter 565 would not emerge from thedistal end of the endoscope 510 at the beginning of the procedure. Next,the endoscope 510 may be inserted into the body of the patient throughan opening, such as the mouth, or through an incision made in the bodyspecifically to accommodate the diagnostic procedure. The endoscope 510would then be guided into position from outside the body of the patientby the practitioner. If necessary the practitioner may turn the lighttip 520 on and use the optical sensor 530 to assist in guiding thedistal end 595 of the endoscope 510 down into its desired restinglocation. Then, once the distal end 595 of the endoscope 510 waspositioned near the tissue to be analyzed the practitioner would extendthe catheter's 565 distal tip 560 out from inside the internal workingchannel 570. The practitioner would then position the distal tip 560 tobe adjacent to the tissue to be analyzed, the orifices 540, located onthe distal tip 560, facing the tissue to be tested. Similar to thepositioning of the endoscope, the practitioner may also illuminate thelight tip 520 and utilize the optical sensor 530 to aid in properlypositioning the distal tip 560 of the catheter 565. Once the distal tip560 of the catheter 565 is properly positioned, the practitioner wouldturn on the vacuum source in order to draw the tissue towards theorifices 540. Once the sensors 550 began to adequately sense the tissue,the practitioner could then adjust the vacuum being drawn through theorifices, either at the source of the vacuum or at the catheter 565through an adjustment valve (illustrated above), so that only therequisite amount of force was utilized to maintain contact between thesensors 550 and the tissue being analyzed.

Now coupled to the distal tip 560 of the catheter, the tissue, inaddition to being analyzed by the sensors 550, may also be manipulatedby the practitioner by moving the catheter at its proximate end (notshown). As required, the tissue may be manipulated within the view ofthe optical sensor 530. Once the required data was obtained by thesensors 550, the vacuum would be reduced until the tissue would bereleased from the orifices 540. If additional tissue testing wasrequired, the procedure would be repeated. Once the requisite testingwas completed the distal tip 560 of the catheter 565 would be withdrawnback into the endoscope 510 so that it no longer extended outside of theendoscope 510. The endoscope 510 would then be removed from the body.

While a light 520 and an optical sensor 530 are shown at the end of theendoscope 510 other diagnostic components can also be placed at the endof the endoscope 510 to assist the practitioner. For example, the sameelectrical and ultrasonic sensors placed on the surface of the distaltip 560 of the catheter may also be placed on the distal end 595 of theendoscope 510 to provide additional sources of data to the practitionerduring the diagnosis.

FIG. 6 illustrates a catheter 60 in accordance with a third embodimentof the present invention. In FIG. 6 the catheter 60 has a catheter body690 containing a sensor line 695. The catheter body 690 is rigidlyconnected to a coupler 680. The coupler 680 has a sensor communicationcable 630 and a vacuum hose 660 protruding from the coupler's 680 lowerside. The vacuum hose 660 has a connection hose 625 sealably connectedto the vacuum hose 660. The connection hose 625 is sized to fit to theconnection hose 625 on one side and to a syringe 615 on the other. Thesyringe 615 is in fluid communication with the orifices 630 via theconnection hose 625, the vacuum hose 660, the coupler 680, and thecatheter body 690. The syringe 615 contains a plunger 605. When theplunger 605 is drawn out, in the direction of the arrow, it creates avacuum force that is ultimately transferred to the orifices 600 at thedistal tip 620 of the catheter 60. This syringe 615 is, therefore, analternative to the vacuum pump described in the previous embodiments.When the syringe 615 is used, the vacuum adjustment valve 675 would berotated until it was completely open so that the practitioner would becontrolling the amount of vacuum force generated at the orifices 600 ofthe catheter 60 by sliding and holding the plunger 605 of the syringe615.

Alternatively, as illustrated in FIG. 7, which is a cross-sectional viewthrough the distal end of a fourth embodiment of the present invention,the sensors 710 and the orifices 700 do not need to be in line with oneanother along the outside surface of the catheter. Instead, they mayalso be placed at different locations of the distal tip 720 of thecatheter. For example, as is evident in FIG. 7 the orifice 700penetrates through the top of the outside surface of the distal tip 720of the catheter while the sensor 710 is positioned along a side of theoutside surface of the distal tip 720 of the catheter. Similarly, whilethe sensors are illustrated on the surface of the catheter they mayinstead be formed in the catheter or placed on the inside wall 755 ofthe distal tip 720 of the catheter. Also, while an endoscope isdescribed in the embodiments above, a flexible tube creating a pathwaymay, instead, be used in its place. Therefore, as will be evident to oneof skill in the art, the above embodiments are merely illustrative ofthe invention disclosed herein and other embodiments may be employedwithout departing from the spirit and scope of the present invention.

What is claimed is:
 1. A method of analyzing tissue within the body of apatient comprising: inserting a catheter having a sensor at a distal endof the catheter and an orifice through and flush with an externalperipheral surface of the catheter and proximate to the sensor into thebody of a patient; applying suction through the catheter, when thesensor is a distance away from the tissue to be analyzed, to draw thetissue away from its initial resting position and towards apredetermined sensing position for the sensor, wherein at least aportion of the tissue is drawn flush with the external peripheralsurface of the catheter and adjacent the sensor; and analyzing thetissue with the sensor.
 2. The method of claim 1 wherein the catheterinserted into the body is carried within an endoscope having a distalend.
 3. The method of claim 2 wherein the distal end of the endoscopecontains a light tip and an optical sensor.
 4. The method of claim 3further comprising: manipulating the catheter to move the tissue towardsthe distal end of the endoscope; and viewing the tissue utilizing theoptical sensor.
 5. The method of claim 1 wherein the suction used todraw tissue within the body is adjustable.
 6. The method of claim 1wherein the sensor is an ultrasound transducer.
 7. The method of claim 1wherein the sensor and the orifice are aligned along a longitudinal axisof the catheter.
 8. A method of analyzing tissue within the body of apatient comprising: extending a catheter having a sensor supported bythe catheter from the distal end of the endoscope to a position adjacentto a preselected tissue to be analyzed; positioning an orifice locatedthrough and flush with an external peripheral surface of the catheter,proximate to the sensor, and adjacent to the preselected tissue to beanalyzed; applying a force to the tissue via the catheter to draw thetissue away from its initial resting position and into a predeterminedsensing position relative to the sensor, wherein at least a portion ofthe tissue is drawn flush with the external peripheral surface of thecatheter and adjacent the sensor, the tissue not touching the sensorwhen in the predetermined sensing position; and analyzing the tissuewith a sensor supported by the catheter.
 9. The method of claim 8wherein the force is applied to the tissue with a negative pressurecreated through the orifice of the catheter.
 10. The method of claim 9wherein the negative pressure is created by sliding a plunger outside ofthe body, the plunger in fluid communication with the orifice of thecatheter.
 11. The method of claim 8 further comprising: illuminating thetissue drawn towards the catheter with a light tip located on the distalend of the endoscope; and viewing the tissue with an optical sensorlocated on the distal end of the endoscope.
 12. A method of testingtissue within the body of a patient comprising: positioning the distalend of an endoscope to a predetermined position adjacent to tissue to betested; extending a catheter, located within the endoscope, out of thedistal end of the endoscope and positioning the catheter in apredetermined position; drawing tissue from its initial resting pointwithin the body of the patient towards the catheter by applying suctionthrough an orifice located through and flush with an external peripheralsurface of the catheter and proximate to a sensor, wherein at least aportion of the tissue is drawn flush with the external peripheralsurface of the catheter and adjacent a sensor; and testing the tissuedrawn towards the catheter with the sensor located on the catheter. 13.The method of claim 12 wherein the sensor is an infrared sensor.
 14. Themethod of claim 12 wherein the endoscope contains an optical sensor. 15.The method of claim 12 wherein the sensor and the orifice are alignedalong a longitudinal axis of the catheter.
 16. An apparatus for testingtissue within the body of a patient comprising: a catheter having afirst end and a second end, the first end having an orifice through aside surface of the catheter, the first end also having a first sensoron a side surface, the first sensor aligned on a first longitudinal axisof the catheter and the orifice aligned on a second longitudinal axis ofthe catheter; an endoscope, having a distal end, surrounding thecatheter; and, a vacuum channel in fluid communication with the orifice.17. The apparatus of claim 16 further comprising a suction adjustmentvalve in fluid communication with the vacuum channel.
 18. The apparatusof claim 17 further comprising: a light tip located on the distal end ofthe endoscope.
 19. The apparatus of claim 16 wherein the first sensor isan optical sensor.
 20. The apparatus of claim 16 further comprising: asecond orifice through the surface of the catheter, the first orificeand the second orifice spaced a predetermined distance apart.
 21. Theapparatus of claim 20 further comprising: a second sensor, the firstsensor and the second sensor located on the surface of the catheter, thefirst sensor and the second sensor spaced a predetermined distance apartfrom one another.
 22. The apparatus of claim 21 further comprising: asensor line in communication with either the first sensor or the secondsensor, the sensor line molded into the side of the catheter.
 23. Adevice for analyzing tissue within the body comprising: a catheter witha distal end; a plurality of orifices and a plurality of sensors alongan external perimeter surface at the catheter's distal end wherein onesensor from the plurality of sensors is aligned along a first perimeterlongitudinal axis defined along the external perimeter surface of thecatheter and a second sensor is located along a second, different,perimeter longitudinal axis defined along the external perimeter surfaceof the catheter; and a vacuum hose in fluid communication with theplurality of orifices.